Andrew Crofts’ second-half header secured the passage for Brighton’s into the fourth round of the FA Cup after the narrow victory at Plainmoor Road.
Torquay dominated the first half but created few chances with Kieran Charnock seeing his header tipped over the bar by keeper Michael Kuipers
But Crofts broke the deadlock with a fine header from Gary Dicker’s corner that flew into the roof of the net.
Nicky Forster also went close but keeper Michael Poke saved his low shot.
In seeing off the Gulls, it is the first time the Seagulls have made the fourth round of the FA Cup in 17 years.
The Torquay United manager Paul Buckle told BBC Radio Devon afterwards: "I’m disappointed not to have gone through. I thought it was going to be a draw because it was a very difficult surface to play on for both teams.
"I thought we more than played our part today and I’m reasonably happy actually.
"We played very well and it’s arguable that we were the better side in the first-half and the second-half but it wasn’t to be and I’m very proud to have got into the third round again with the players."